Pen position regulator

ABSTRACT

A pen exchange mechanism is disclosed, by which a plurality of pen chuck mechanisms holding pens on a carriage are disposed, and a slider is engaged with the carriage at a position corresponding to a pen, which should print, among said pens, printing being effected while driving a pen chuck mechanism at a position corresponding to the slider together with the pen by means of a pen driving mechanism.

This application is a division of application Ser. No. 98,542, filedSept. 18, 1987, U.S. Pat. No. 4,845,516.

FIELD OF THE INVENTION

This invention relates to a pen type printer utilized in a printereffecting printing etc. by means of pens.

BACKGROUND OF THE INVENTION

In general, there are printers having a construction by which printingetc. are effected by means of pens, which are a kind of deviceoutputting various sorts of information.

A printer using these pens is so constructed that pen chuck mechanismsare mounted on a carriage moving relatively with respect to a surface tobe printed, a plurality of pens having different colors are mounted onthese pen chuck mechanisms, respectively, and printing is effected byselecting a pen having a color to be printed so that color printing canbe easily effected.

However, in a printer using conventional pens, printing etc. is effectedby using special pens prepared separately for each model of printers andit was not possible to effect printing etc. by means of pens sold in themarket. Of course, it was not possible to select freely the nature ofthe ink and the size of printed letters. Further, in a prior art printerprinting etc. only of colors previously prepared can be effected and itis impossible to effect printing of a color selected freely amoung colorpens sold in the market. In addition, according to the prior arttechniques, since every pen was formed to be small in order to mount aplurality of pens on a pen chuck mechanism, the amount of ink was small,ink was often exhausted in the course of a printing etc., which obligedexchange of the pens. Furthermore it was feared that discontinuity wasproduced in the print due to the exchange of pens.

OBJECT OF THE INVENTION

This invention takes these points into account and its object is toprovide a cheap pen type printer of simple construction permittingchange-over of pens used for the printing etc. in a simple manner, inthe case where the printing etc. is effected by using various pensdifferent in thickness, length, form, etc.

SUMMARY OF THE INVENTION

A pen exchange mechanism according to this invention comprises acarriage moving relatively and parallel with respect to a surface to beprinted; a plurality of pen chuck mechamisms supported by the carriagefreely movably in the direction perpendicular to the surface to beprinted together with pens held thereon; a slider mounted movablyrelatively between driving positions corresponding to the pen chuckmechanisms with respect to the carriage and at the driving positionsengaged with the carriage in one body; and a pen driving mechanismdisposed on the slider so as to drive a corresponding pen chuckmechanism towards the surface to be printed at each of the drivingpositions.

By the pen exchange mechanism according to this invention a plurality ofpen chuck mechanisms are disposed and a slider is engaged with thecarriage at a driving position corresponding to a pen, which is printingamong these pens. In this state printing etc. is effected by driving apen chuck mechanism, which is at a position corresponding to the slidertogether with a pen, by means of a pen driving mechanism and bythrusting the pen against a surface to be printed.

Next, in the case where the pen effecting printing etc. should beexchanged, the slider at the driving position corresponding to the penused at that time is disengaged from the carriage so that both themembers are put in a state where they are freely movable with respect toeach other. After that, the slider is moved to a relative drivingposition corresponding to a pen, which should be used subsequently, withrespect to the carriage and the slider and the carriage are engaged witheach other at that position. In this way an exchange of a used pen to anew one which should be used for printing is terminated. The new pen isdriven by the pen driving mechanism thereafter in order to effectprinting etc.

A pen chuck mechanism according to this invention comprises a sleevesupported by a carriage moving relatively and parallel with respect to asuface to be printed freely movably in the direction perpendicular tothe surface to be printed; and a plurality of holding nails disposed onthe sleeve, a pen being able to be inserted and extracted in and fromthe space surrounded by the holding nails in the direction perpendicularto the surface to be printed and to be held by them elastically.

By the pen chuck mechanism according to this invention it is possible tohold e.g. any one of various pens sold in the market while effectingcorrect centering of the nib of the pen by an extremely simple operationto thrust a pen with the nib directed towards the surface to be printedin the space surrounded by the holding nails disposed on the sleeve.

That is, the pen is held by the elasticity of the holding nails. Inaddition, since the holding force of the holding nails is stronger atthe extremity on the side of the surface to be printed than at theextremity on the other side, the centering of the nib of the pen can beeffected correctly and at the same time a pen, which is tapered to bemore and more slender towards the nib of the pen, is held with a forcesufficiently strong.

Consequently printing etc. can be effected with a pen arbitrarilyselected, depending on the purpose such as printing etc.

A pen position regulating mechanism according to this invention, inwhich a pen is held by a pen chuck mechanism holding the pen insertedtowards a surface to be printed and freely movable in the directionperpendicular to the surface to be printed so that the extremity thereofis in accordance with a mounting reference position predeterminedtherefor, is characterized in that it comprises further a simultaneousmovement distance regulating member, which regulates the distance overwhich the pen chuck mechanism can move towards the surface to be printedat the same time as the pen, when the pen is inserted in the pen chuckmechanism, and a separate movement distance regulating member, whichregulates the distance over which the pen can move alone in the samedirection after the pen chuck mechanism has been stopped.

In the pen position regulating mechanism according to this invention,when a pen is inserted towards the surface to be printed into a penchuck mechanism, both the pen and the pen chuck mechanism move at thesame time towards the surface to be printed by the friction. Then, whenthey move at same time to some extent, the movement towards the surfaceto be printed of one of them, i.e. the pen chuck mechanism, is preventedby the simultaneous movement distance regulating member. After that,when the pen is further thrusted, only the pen continues to be thrustedtowards the surface to be printed. When only the pen is advanced to someextent, the displacement of the pen alone is also prevented by theseparate movement distance regulating member. In this state, when thethrusting force on the pen is removed, the pen and the pen chuckmechanism return together by the distance, over which the pen chuckmechanism has been displaced. This return distance is constant for anypen, because it is always the distance regulated by the simultaneousmovement distance regulating member. Consequently the pen is mounted ina state where the nib of the pen is held always at a constant heightfrom the surface to be printed, i.e. it is in accordance with themounting reference position in the pen chuck mechanism.

A printing method according to this invention comprises the steps offorming a plurality of pen chuck mechanisms holding pens freely movableup and down on a carriage moving parallel and relatively to a surface tobe printed; forming position correcting means displacing and regulatingthe caridge and a sheet of paper to be printed in two directions, whichare perpendicular to each other, in order to position a specified pen onthe pen chuck mechanism at a predetermined printing position, anddisposing a memory storing change-over strokes for changing-over thepens in the position correcting means, the displacement and theregulation of the carriage and the sheet of paper being controlled bythe memory.

By the printing method according to this invention, since the positioncorrecting means regulating the displacement of the carriage and thesheet of paper and positioning a specified pen at its initial positionincludes a memory storing change-over strokes for changing-over thepens, even if the pen, which should print, has been changed, the newlymounted pen can move correctly to the predetermined position thereforand therefore it is possible to print with various colors by means of aplurality of pens having a large size.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a whole printer according to an embodiment ofthis invention;

FIG. 2 is an enlarged plan view of the carriage and the slider of theprinter indicated in FIG. 1;

FIG. 3 is a cross-sectional view along the III--III line in FIG. 2;

FIG. 4 is a transversal plan view of a pen chuck mecanism of the printerindicated in FIG. 1;

FIG. 5 is a cross-sectional view along the II--II line in FIG. 2;

FIGS. 6 and 7 are the same figures as FIG. 5 in a middle stage at theselection and at the printing, respectively, at the driving position A;

FIG. 8 is an exploded perspective view illustrating the construction ofan engaging mechanism, a pen driving mechanism, etc. of the printerindicated in FIG. 1;

FIG. 9 is a plan view similar to FIG. 1, indicating a second embodimentof this invention; and

FIG. 10 is a block diagram showing the construction of a control unit.

DETAILED DESCRIPTION

Hereinbelow some preferred embodiments of this invention will beexplained more in detail, referring to FIGS. 1 to 10.

At first, an approximate construction of a printer using a pen exchangemechanism 1, which is an embodiment of this invention, will beexplained. In the printer of this embodiment, as indicated in FIGS. 1and 3, a base plate 4, to the upper surface of which a sheet of paper 3is supplied between frames 2, 2 disposed fixedly at the two extremitiesin the width direction, is arranged horizontally. Hereinbelow the uppersurface of this base plate 4 is called the surface to be printed. Abovethis base plate 4 an upper fixed shaft 5 and a lower rotational shaft 6are transversally mounted parallel to each other. A carriage 7, on which4 pen chuck mechanisms 8, 8, . . . driven selectively by the penexchange mechanism 1 of this embodiment are disposed, is mounted on afixed shaft 5 and rotational shaft 6 freely slidably in the axialdirection by a bearing not shown in the figure. Further within thecarriage 7 is disposed a slider 9, which is mounted on the two shafts 5and 6 freely slidably in the axial direction by a bearing not shown inthe figure in the same way as the carriage 7. In addition, this slider 9and the carriage 7 can be engaged with each other in one body through anengaging mechanism 10 so that they can move together or separately withrespect to each other. Furthermore the two extremities of a carriagedriving cord 13 such as a belt wound round a driving wheel 11 and adriven wheel 12 disposed on the outer side of the frames 2,respectively, are fixed to the two extremities of the carriage 7 in theaxial direction. When the slider 9 and the carriage 7 are engaged in onebody with each other through the engaging mechanism 10, they are drivenforward and backward in the axial direction of the shafts 5 and 6, whichis the X direction, parallel to the surface to be printed P, by movingthe carriage driving cord 13 through the driving wheel 11. On thecontrary, the sheet of paper 3 is forwarded in the Y direction, which isperpendicular to the X direction, by a sheet forwarding roller 14.Desired printing etc. are effected by combining these movements in the Xand Y directions.

On the other hand, on the carriage 7 are disposed four pen chuckmechanisms 8, 8, 8, 8 on both the sides of the shafts 5 and 6 in the Ydirection two by two. Each of these pen chuck mechanisms 8 consists of asleeve 16 having a cylindrical shape mounted freely movably forward andbackward up and down in the direction perpendicular to the surface to beprinted P in a sleeve guide 15 on the carriage 7 and a plurality (threein this embodiment) of holding nails 17, 17, 17 disposed with a constantinterval in the peripheral direction on the inner surface of the sleeve16. The sleeve 16 and these holding nails 17 are made of a syntheticresin, etc. in one body. The sleeve 16 is always energized upward by acompression spring 18 inserted between the lower extremity of the sleeve16 and the bottom plate 7a of the carriage 7 in such a direction that itis made more distant from the surface to be printed P, and it is stoppedby bringing its upper extremity into contact with an upper stopper 15aof the sleeve guide 15. The holding nails 17 hold elastically a pen 19inserted in the space surrounded by them. In this embodiment the holdingnails 17 are so formed that they hold a pen sold in the market as thepen 19. Since the cross section of most of pens sold in the market ishexagonal or circular, in order to hold satisfactorily both of them, thenumber of the holding nails is preferably 3 or 6 as in this embodiment.The holding nails 17 are long in the up and down direction and convextowards the outside. Further, in order to hold the pen 19 elastically,they are so formed that the inner diameter of the circle formed by theholding nails 17 is smaller than the outer diameter of the pen 19, asindicated by two-dot-one-dashed lines in FIG. 3, in the free state whereno pen 19 is held by them. In addition, in order to effect surelycentering of the nib 19a of the pen 19 in a simple manner and to holdsurely the pen 19, which is usually a pen sold in the market tapered inthe most case more and more slender towards the nib 19a, with asufficient force, the elastic force of each of the holding nails isstronger at the lower extremity, which is closer to the nib 19a than theother, than at the upper extremity. In order to increase the elasticforce holding the pen 19 by means of the holding nails 17, it ispreferable to dispose an elastic auxiliary member 20 consisting of e.g.a gum band, a spring, etc. round the periphery at an arbitrary positionin the proximity of the upper extremity of the holding nails 17, asindicated in FIG. 3. A pen position regulating mechanism 21 is disposedin each of the pen chuck mechanism 8. This pen position regulatingmechanism 21 makes the holding nails 17 hold the pen 19 so that the nib19a thereof is at the mounting reference position projecting over apredetermined distance from the sleeve 16, i.e. that it is located at apredetermined height H from the surface to be printed P, in order toobtain always excellent printing. For this reason, in this pen positionregulating mechanism 21, a projection 23 is disposed on the outside ofthe sleeve 16 towards the slider 9 and a positioning stopper 24 isdisposed on the slider 9, which stopper 24 stops the descent of thesleeve 16 by the fact that the descending projection 23 is brought intocontact therewith, as an example of the simultaneous displacementdistance regulating member for regulating the distance over which thepen chuck mechanism 8 moves towards the surface to be printed P togetherwith the pen 19. Furthermore, as an example of the separate displacementdistance regulating member for regulating the distance over which thepen 19 can move alone further towards the surface to be printed P, afterthe pen chuck mechanism 8 has been stopped, the surface to be printed Pis disposed to stop the descent of the pen 19 by the fact that the nib19a is brought into contact therewith. As indicated in FIG. 3, they areso disposed that the distance H between the lower surface of theprojection 23, when the sleeve 16 is stopped at the uppermost position,and the upper surface of the positioning stopper 24 is equal to theheight H of the nib 19a of the pen 19 at that time measured from thesurface to be printed P. The projections 23, 23, 8, 8 disposedprojectingly from each of the four sleeves 16 are arranged withpositional intervals in the axial direction of the shafts 5 and 6. Thisposition in the axial direction of each of the projections 23 is thedriving position, where each of the pen chuck mechanisms 8 is driventogether with the pen 19 towards the surface to be printed P. In thisembodiment, the driving positions of the four pen chuck mechanisms 8, 8,carriage are represented by A, B, C and D in the order of left-bottom,left-top, right-bottom and right-top.

Further, on the slider 9, which is the other of the two members, aredisposed an engaging mechanism 10, which engages and disengages theslider 9 with and from the carriage 7, and a pen driving mechanism 22driving the pen 19 held by the pen chuck mechanism 8 towards the surfaceto be printed P. Both of engaging mechanism 10 and pen driving mechanism22 use a worm 25 supported freely movably at the lower portion of theslider 9 as a driving source. This worm 25 has an oval cross section andis mounted on the rotational shaft 6, which is a kind of serrated shaft,freely slidably in the axial direction. Further, on the slider 9, acenter shaft 26 is mounted above the worm 25 in the transverse directionparallel to the Y direction. On this center shaft 26 is mounted freelyrotatingly a sector worm gear 27, which is engaged with the worm 25. Toone side of this sector worm gear 27 is secured an engaging cam 28,which is one component of the engaging mechanism 10. Further, on theother side surface of the sector worm gear 27 is mounted freelyrotatingly a driving cam 26, which is one component of the pen drivingmechanism 22, on the center shaft 26.

This engaging mechanism 10 will be explained below, referring to FIGS. 2to 8. A lock lever 31 is supported freely movably upward and downwardabove the engaging cam 28 by a lock lever guide 30 formed on the slider9. This lock lever 31 is moved up and down by the engaging cam 28 at itslower extremity and energized downward by a compression spring 33inserted between a spring receiving seat 32 formed on the lock lever 31and the ceiling portion of the slider 9. Further, on the upper endportion of the lock lever 31 is formed a contacting surface 34 having asemicircular form, which is brought into contact with the outerperipheral surface of the fixed shaft 5. In addition, on the sidesurface of the lock lever 31 opposite to the sector worm gear 27 isdisposed an a engaging wedge 35. On the carriage 7 are formed 5 engagingrecesses 36, 36, . . . opened upward, with and from which this engagingwedge 35 is engaged and disengaged. These 5 engaging recesses 36, 36,36, 36, except for the engaging recess 36 at the central position inFIG. 8, correspond to the driving positions A, B, C and D describedabove in the order of left to right. The central engaging recess is usedfor mounting and dismounting of the pen 19 to and from the pen chuckmechanism 8. As indicated in FIG. 7, in the case where the engagingwedge 35 of the lock lever 35 is engaged with either one of the engagingrecesses 36 of the carriage 7, the slider 9 and the carriage 7 movetogether in one body. Further, as indicated in FIG. 6, in the case wherethe engaging wedge 35 is disenaged from all of the engaging recesses 36and the contacting surface 34 of the upper end portion of the lock lever31 is brought with the lower half portion of the outer peripheralsurface of the fixed shaft 5, the slider 9, which is one of the members,is supported fixedly between the two shafts 5 and 6 and at this statethe carriage 7, which is the other of the members, moves relatively withrespect to the slider 9 by moving in the X direction.

Now the pen driving mechanism 22 will be explained below, referring toFIGS. 2 to 8. The driving cam 29 has an approximately circular formconsisting of a larger arc portion and a smaller arc portion connectedto each other. In the larger arc portion is formed an arc shapedthroughhole 37, whose center is the center shaft 26 and in the smallerarc portion is disposed a pen driving lever 38 driving a projection 23,which is opposite in the Y direction to the slider 9, towards thesurface to be printed P on both sides in the Y direction. These pendriving levers 38, 38, . . . extend from cut-off portion of the sectorworm gear 27 to both the sides in the Y direction. Further, on the sidesurface of the sector worm gear 27 on the side surface of the side ofthe driving cam 29 is disposed projectingly an arc shaped projection 39having a center angle, which is smaller than the center angle of the arcshaped throughhole 37 and this arc shaped projection 39 is inserted inthe arc shaped throughhole 37 so that it can rotate relatively in theextent of the difference between the two center angles. In the arcshaped throughhole 37 of driving cam 29 is inserted a compression spring41 between a spring receiving seat 40 projectingly disposed on thesector worm gear 27 and the end surface of the arc shaped throughhole37, which spring gives the sector worm gear 27 and the driving cam 29 aforce rotating them in the directions opposite to each other. Thiscompression spring 41 brings, as indicated in FIG. 6, the clockwise endsurface of the arc shaped throughhole 37 and that of the arc shapedprojection 39 into contact with each other, in the case where the nib19a of the pen 19 is not elastically thrust against the surface to beprinted P. Further, in the positioning stopper 24 disposed on both thesides of the Y direction of the slider 9 is formed a refuge recessportion 42 so that, in the case where the nib 19a of the pen 19 isbrought into contact with the surface to be printed P in order to effectprinting etc., the projection 23 disposed projectingly on the sleeve 16in each of the pen chuck mechanisms 8 descends below the upper surfaceof the positioning stopper 24.

Now, as indicated in FIG. 1 in detail, on the carriage 7 described aboveare formed four pen chuck mechanisms 8 in total, two longitudinal andtwo transverse, at positions corresponding to the four apices of arectangle on a plane. The interval between two of the pens 19A, 19B, 19Cand 19D mounted on each of the pen chuck mechanism 8 is a in the Xdirection and b in the Y direction. Printing is begun, after specifiedpens 19 have been positioned at their predetermined initial positions.For this reason, it is necessary to regulate operation while moving thecarriage 7 in the X direction and at the same time to regulate operationwhile moving the sheet of paper 3 in the Y direction. Positioncorrecting means 50 therefor is disposed, as indicated in FIG. 10. Theposition correcting means 50 is connected electrically with penselecting means 51 for selecting a pen which is to be used for printingso that a selection signal 52 for a specified pen 19 selected by thispen selecting means 51 is output from the pen selecting means 51 to theposition correcting means 50. Further this position correcting means 50is provided with a memory 53 for storing change-over strokes forchanging-over pens 19 and in this memory 53 is formed a tablerepresenting the changing-over strokes divided into two groups, onerelating to the X direction and the other to the Y direction as shown inTable 1.

                  TABLE 1                                                         ______________________________________                                        Pen change-over X direction                                                                             Y direction                                         ______________________________________                                        19A → 19B                                                                              +a        0                                                   19A → 19C                                                                              0         +b                                                  19A → 19D                                                                              +a        +b                                                  19B → 19A                                                                              -a        0                                                   19B → 19C                                                                              -a        +b                                                  19B → 19D                                                                              0         +b                                                  19C → 19A                                                                              0         -b                                                  19C → 19B                                                                              +a        -b                                                  19C → 19D                                                                              +a        0                                                   19D → 19A                                                                              -a        -b                                                  19D → 19B                                                                              0         -b                                                  19D → 19C                                                                              -a        0                                                   ______________________________________                                    

Furthermore the position correcting means 50 described above isconnected electrically with the means 54 for driving the sheet of paper3 and the means 55 for driving the carriage 7 so as to be able to driveat least one of the sheet of paper 3 and the carriage 7 by the strokeaccording to Table 1. In addition the position correcting means 50described above is connected electrically also with a lifting means 56for raising and lowering each of the pens 19 mounted on the pen chuckmechanism 8 in the carriage 7.

Now the operation of this embodiment will be explained below.

At first the mounting of the pen 19 on each of the pen chuck mechanisms8 is effected in the state where the engaging wedge 35 projectinglydisposed on the lock lever 31 is engaged with the engaging recess 36 atthe central position in the X direction formed in the carriage 7. Inthis case the positioning stopper 24 is under the projection 23 on eachof the pen chuck mechanisms 8. The mounting of the pens 19 on the penchuck mechanisms 8 is explained for one pen chuck mechanism 8. Throughthe opening formed in the proximity of the upper stopper 15a of thesleeve guide 15 disposed on the carriage 7 the nib 19a of a pen 19 isthrust towards the surface to be printed P in the space surrounded bythe holding nails 17 within the sleeve guide 15 so as to insert ittherein. This pen 19 is inserted downward therein while thrusting theholding nails 17 outward against their elastic force. When the pen 19 isinserted to some extent, the frictional force between the pen 19 andeach of the holding nails 17 becomes stronger than the elastic force ofthe compression spring 18 and the sleeve 16 begins to descend againstthe elastic force of the compression spring 18. After that the descentof the sleeve 16 and the holding nails 17 is stopped physically by thefact that the projection 23 projectingly disposed on the sleeve 16 isbrought into contact with the positioning stopper 24. Then, when the pen19 is further thrust, the pen is further inserted while thrustingoutward the holding nails 17, the descent of the nib 19a of the pen 19is stopped physically by the fact that it is brought into contact withthe surface to be printed P. In this state, when the thrusting force onthe pen 19 is removed, the sleeve 16, the holding nails 17 and the pen19 are raised all together by the resilient force of the compressionspring 18 and they are stopped at their highest position by the factthat the upper end surface of the sleeve 16 is brought into contact withthe upper stopper 15a of the sleeve guide 15. At this time the nib 19aof the pen 19 is positioned at the mounting reference positionprotruding from the lower extremity of the sleeve 16 over apredetermined distance and at the same time at a position, which ishigher than the surface to be printed P by a predetermined height H. Inthis way a pen 19 having an arbitrary shape is mounted so that its nib19a is always in accordance with a constant mounting reference positionand following printing etc. its movement can be effected satisfactorily.Further the pen 19 is held elastically by the holding nails 17. Inaddition centering of the nib 19a can be performed correctly by the factthat the elastic force in the lower end portion of the holding nails 17is stronger than that in the upper end portion and at the same time,even if extremity of the pen is tapered so as to be more and moreslender, it can be held with a sufficient holding force. As explainedabove, by using the pen chuck mechanisms 8 of this embodiment it ispossible to hold various pens having an arbitrary thickness, length andshape by an extremely simple operation, while performing the centeringof the nib 19a correctly. Thus printing etc. can be effected arbitrarilywith a pen sold in the market and it is possible also to select thecolor and the property of the ink, the size of printed letters, etc.

Next the pen 19 to be used for printing etc. is selected. This operationfor selecting the pen 19 is identical to the operation for changing-overthe pen 19 used for printing etc.

Now suppose that the pen 19, which is at the left bottom in FIG. 1, isselected. At first, starting from the state indicated in FIG. 5, therotational shaft 6 and the worm 25 are rotated by means of a drivingmotor not shown in the figure so that the sector worm gear 27 is rotatedclockwise in the same figure. In this way the engaging cam 28 is rotatedclockwise in the same figure together with the sector worm gear 27 andthe lock lever 31 is raised by the engaging cam 28 against the elasticforce of the compression spring 33. As this lock lever 31 is raised, theengaging wedge 35 is separated upward from the engaging recess 36 formedin the carriage 7 and the carriage 7 and the slider 9 are in the statewhere they are freely relatively movable. Then, when the lock lever 31is further raised, the rotation of the rotational shaft 6 is stopped inthe state where the contacting surface 34 of the upper end portion iscontacted strongly with the lower half surface of the fixed shaft 5. Inthis way the slider 9 is fixed by the fact that the lock lever 31, theengaging cam 28, the sector worm gear 27 and the worm 25 are stronglystretched between the two shafts 5 and 6. Then only the carriage 7 isdisplaced towards right by driving the caridge driving cord 13 throughthe driving wheel 11 and when the slider 9 reaches the driving positionA, the displacement of the carriage 7 towards right the is stopped. Thisstate is represented in FIG. 6. After that, the rotational shaft 6 isrotated inversely, which rotates the sector worm gear 27counterckockwise in FIG. 6 through the worm 25 and lowers the lock lever31 by the resilient force of the compression spring 33 so as to followthe engaging cam 28 so that the engaging wedge 35 is engaged with theengaging recess 36 at the left end in FIG. 6 corresponding to thedriving position A. When this engaging wedge 35 and the engaging recess36 are perfectly engaged with each other, the descent of the engagingwedge 35 is prevented by the engaging recess 36 and the selection of thepen 19 is terminated. The carriage 7 and the slider 6 are united in onebody by this engagement of the engaging wedge with the engaging recess36 and displaced thereafter together in the X direction by the drivingwheel 11. At the selected driving position A in FIG. 6, just under theprojection 23 a refuge recess 42 formed in the positioning stopper 24 isopposed thereto, which enables the pen 19 to descend.

Next for effecting printing etc. the sector worm gear 27 is furtherrotated counterclockwise in FIG. 6 by rotating further the rotationalshaft 6. The rotational force of this sector worm gear 27 is transmittedto the driving cam 29 through the compression spring 41 and the drivingcam 29 rotates also counterclockwise in the same figure together withthe pen driving lever 38. This pen driving lever 38 is brought intocontact with the projection 23 projectingly disposed on the sleeve 16 inthe pen chuck mechanism 8, while rotating counterclockwise, which lowersthe pen 19 together with the sleeve 16 towards the surface to be printedP. As the rotation of the pen driving lever 38 progresses, the nib 19aof the pen 19 is brought into contact with the surface to be printed P.Although, in this state, the rotation of the driving cam 29 isprevented, further in this embodiment only the sector worm gear 27 isrotated in the same direction and as indicated in FIG. 7, disengages thearc shaped projection 39 of the sector worm gear 27 from the clockwiseend surface of the arc shaped throughhole 37 formed in the driving cam29, which brings elastically the nib 19a of the pen 19 into contact withthe sheet of paper 3 through the elastic force of the compression spring41. Since the nib 19a of the pen 19 is brought elastically into contactwith the sheet of paper 3, this contacting state between the nib 19a andthe sheet of paper 3 absorbs fabrication errors of each of thecomponents of the printer, mounting errors of the pen 19 on the penchuck mechanism 8, differences in the thickness of the sheet of paper 3and unevenness of the sheet of paper 3 so that the nib 19a is broughtinto contact with the sheet of paper 3 always with a constant contactingpressure and therefore extremely good printing can be obtained. Inpractice, in the state where the nib 19a of the pen 19 is brought intocontact with the sheet of paper 3, printing etc. is performed accordingto printing instructions on the sheet of paper 3, while moving thecarriage 7 and the slider 9 in the X direction and the sheet of paper 3in the Y direction.

Next for changing-over the pen 19, which is used to perform printingetc., the nib 19a of the pen 19 is separated from the sheet of paper 3by rotating the rotational shaft 6 so as to rotate the sector worm gear27 clockwise in FIG. 7 and a following new pen is selected in the sameway as for the selection of the pen 19. Thereafter printing etc. areeffected by means of the new pen 19 in the same way as describedpreviously.

As explained above, according to this embodiment, the exchange of thepen 19 can be effected extremely simply. Further the construction of theprinter is also simple and it is cheap.

FIG. 9 shows another embodiment of this invention.

In this embodiment four pen chuck mechanisms 8, 8, 8,8 are arranged onone straight line in the X direction and the other parts of theconstruction are identical to that indicated in the precedingembodiment. By arranging the pen chuck mechanisms 8 as described in thisembodiment it is possible to enlarge the extent where printing etc. canbe effected in the Y direction with respect to the sheet of paper 3, byusing all these four pens 19, 19, 19,19.

Furthermore, when the number of pens 19 arranged in the X direction isreduced as described in the preceding embodiment, it is possible toenlarge the extent where printing etc. can be effected in the Xdirection with respect to the sheet of paper 3, by using all these pens19, 19, 19,19.

Consequently, in the setting of the extent where printing etc. can beeffected by means of all the pens 19, 19, 19,19, the arrangement of thepens 19 in the X and Y directions may be determined according to thecontent of the printing etc. which the printer should perform.

Since the pen type printer mechanism is constructed as explained above,various pens having different thicknesses, lengths and forms can beheld, while effecting the centering of the nib correctly and it ispossible to effect printing etc. always with a suitable pressure.Furthermore effects can be obtained that the pen, which is used for theprinting etc., can be changed-over easily and that the printer has asimple construction and it is cheap. In addition, according to theprinting method by means of a pen type printer according to thisinvention an effect can be obtained that a desired printing can beeffected by positioning each of a plurality of pens at its initialposition predetermined therefor.

While particular embodiments of the invention have been shown anddescribed, it will be obvious to those skilled in the art that variouschanges and modifications may be made without departing from the presentinvention in its broader aspects.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. In a pen positionregulating mechanism, in which a pen is held by a pen chuck mechanismholding said pen inserted towards a surface to be printed and freelymovable in the direction perpendicular to said surface to be printed sothat the extremity thereof is in accordance with a mounting referenceposition predetermined therefor, the improvement wherein it comprisesfurther a simultaneous movement distance regulating member, whichregulates the distance over which said pen chuck mechanism can movetowards said surface to be printed at the same time as said pen, whensaid pen is inserted in said pen chuck mechanism, and a separatemovement distance regulating member, which regulates the distance overwhich said pen can move alone in the same direction after said pen chuckmechanism has been stopped.
 2. A pen position regulating mechanismaccording to claim 1, wherein said pen chuck mechanism consists of acylindrical sleeve freely movable in the direction perpendicular to thesurface to be printed and holding nails disposed at the inside of saidsleeve and holding elastically a pen, and said simaltaneous movementdistance regulating member consists of a positioning projection disposedon said sleeve and a positioning stopper stopping the movement of saidholding nails, said separate movement distance regulating member beingsaid surface to be printed.